TRANSGENIC MOUSE SHARED RESOURCE ABSTRACT The availability of the Transgenic Mouse Shared Resource (TMSR) enables our investigators at the Moores Cancer Center (MCC) to conduct versatile, cutting-edge research with a battery of sophisticated genetic techniques for manipulation of the mouse genome to create models for studies of cancer for incisive in vivo mechanistic investigations of the fundamental processes involved in the etiology of tumor development and metastasis. Transgenic mice carrying new or novel genes are created by microinjection of DNA into the pronuclei of fertilized eggs, specific deletions and mutations are created using CRISPR/Cas9 technology, and ?knock-out? mice that have deleted or modified genes of interest are created by homologous recombination in embryonic stem cells followed by injection into blastocysts to create chimeric mice for breeding to homozygosity. The high degree of conservation of most sequences in genomes of humans and mice makes using mouse genetic manipulation technology to create models of human cancer pathogenesis extremely useful. These approaches are remarkably powerful in cancer research, particularly in the analysis of oncogenes, metastasis, cell-cycle control, tumor suppressor genes, and in the crafting of cancer model systems for developing new treatment regimens, and methods for drug testing and tumor imaging. The mission of this Shared Resource is to provide the highly technical aspects of manipulation of genes in embryos and mouse embryonic stem cells as a service to MCC members, to create the genetically manipulated mouse models they need. This is an example of how specialized techniques, highly trained and dedicated personnel, and expensive equipment can be accessed by researchers who could not reasonably expect to develop or obtain them on an individual basis. The TMSR provides cutting-edge, rapidly advancing, efficient, cost-effective services that adapt to the needs of our users, drive the field of mouse genetics, and continue to be very responsive to the vast creativity of the CCSG membership, fulfilling their needs for the most cutting-edge embryology and molecular genetics in the mouse.